1. Field of the Invention
This invention relates to the seating art and more particularly to an improved adjustable seating arrangement particularly adapted for providing variable contour back and/or seat portion to accommodate various configurational deformities to the user.
2. Description of the Prior Art
Many persons, including both adults and children, are unfortunately afflicted with various disorders causing postural configuration abnormalities which vary from the normal configuration of persons not so afflicted. For example, many suffering from cerebral palsy or muscular dystrophy have their upper torso, and/or buttocks, and/or upper legs twisted or otherwise in configurations that can differ considerably from the generally planar array generally associated with those same portions of the anatomy of persons not so afflicted. The distortions from the planar array can vary throughout the length of each of the body portions so that, for example, a chair back or chair seat having a single variation from the planar extending throughout the extent thereof cannot provide the desired support throughout the extent of each body portion.
There have heretofore been provided various adjustable seating arrangements which attempt to provide seating arrangements for such unfortunately disabled people. For example, in U.S. Pat. No. 4,367,897 there is shown a seating arrangement having a matrix of hard plastic elements connected to rigid tubular elements within a frame. Tensioning means are provided in the matrix but the tensioning means are not connected to the frame. The tensioning means only apply tension through the ball elements to various of the tube elements. Such an arrangement is comparatively costly and cannot provide the desired seating comfort or convenient contour arrangement often desired.
In U.S. Pat. No. 3,088,773 there is shown a frame having spaced apart rigid elements to which the seating and back portions are attached. In this arrangement the transverse strips are elastic and the ties and flexible. Inner members between the frames are rigid metal. There is no provision for adjusting the tension and the ties are not directly connected to the transverse strips and contouring cannot be provided.
In U.S. Pat. No. 3,913,978 there is a rigid seat and back unit coupled to a frame. In some embodiments described therein there are buckles for attaching the frame to the seat back unit. However, there is no provision for providing the desired contour to match the various bodily contours for the disabled persons for whom such a seat is desired.
In U.S. Pat. No. 4,928,334 there is shown a fabric web which is elastic and utilized as a spring element in an upholstered article of furniture such as a seat or a bed and the elastic fabric web is joined to a rigid frame members. No adjustment of contours is shown.
U.S. Pat. No. 3,363,667 shows the structure for attaching a webbing to the frame of a tubular chair such as a lawn chair but does not provide any contour adjustment to either the seat or the back.
U.S. Pat. No. 3,188,662 shows a chair for convalescent persons and provides mechanical movement of the back relative to the seat. No adjustments for contour configuration are shown.
U.S. Pat. No. 4,077,669 shows a resilient seating arrangement but has no adjustments and no spaced apart frame members. U.S. Pat. No. 3,154,345 shows a chair construction apparently intended to be used near water on, for example, boats and ships, and preferably utilizes rectangular cross-section elements as the frame and has a series of interwoven web members connected to the frame. No contour adjustment is shown or suggested.
Other seating arrangements are shown, for example, in U.S. Pat. Nos. 4,544,614, 2,459,843 and 2,485,111. None of these patents shows or suggests the desired contour configuration adjustability.
Other prior art seating arrangements for such disabled persons generally consist of costly complex and cumbersome solid seat inserts with many mechanical adjustments or multiple pieces of foam applied to achieve the desired contour for each individual persons. Such units are difficult to transport and tend to lose their adjustment so that the contours do not remain constant for the person. An individual custom molded contour chair covered with a padded cover has also been utilized but such units are very costly and need significant lead time. Further, should the contours of the individual change, as they often do with many diseases, and/or as the size of a person increases such as when a child grows, the molded contour chair cannot accommodate the changes.
Accordingly, there has long been a need for a seating arrangement for handicapped persons wherein the seating arrangement can provide adjustable contours throughout the back portion and/or seat portion in one, two or three dimensions to accommodate a wide variety of configurational disabilities of a user and also allow for convenient changing of the contours as the need arises for any individual person.